This sounds correct, the correct term being a larger “Stroke Volume” - ie the amount of blood in mls ejected with each heart beat. HR x stroke volume = cardiac output (typically around 5 litres/min in a resting healthy male)
The current thinking is that endurance training increases the internal dimensions of the heart chambers, and that strength training increases the thickness of the heart muscle walls and may in fact reduce the Left Ventricular cavity dimension.
Another factor is the contractility of the myocardium (heart muscle). ie the harder the muscle can contract, the more blood can be ejected.